Apparatus for changing anode blocks in an aluminum furnace and for tapping and refilling said furnace

ABSTRACT

Apparatus for changing anode blocks in an aluminum furnace and for tapping and refiling the furnace provided with a anode changing device being adapted to travel along a mobile horizontal member; gripper means for handling an anode block; means for operating an anode clamp and a reservoir having its outlet directed towards the furnace; a lifting mechanism adapted to convey a tapping device and a reservoir on the horizontal member and having an outlet which is directed towards the filling opening of a silo associated with the furnace.

. 30, 1973 L. A. WETERINGS 9J APPARATUS FOR CHANGING ANODE BLOCKS IN AN ALUMINUM FURNACE FOR AND FOR TAPPING AND REFILLING SAID FURNACE F-ild July 2, 1971 IN VENTOR Low 5 ADE/AA WER'F 5 United States Patent 3,769,195 APPARATUS FOR CHANGING ANODE BLOCKS IN AN ALUMINUM FURNACE AND FOR TAPPING AND REFILLING SAID FURNACE Louis Adriaan Weterings, Utrecht, Netherlands, assignor to N-V. Nederlandse Kraanbouw Mij, Utrecht, Netherlands Filed July 2, 1971, Ser. No. 159,339

Int. Cl. C22d 3/02, 3/12 US. Cl. 204-244 9 Claims ABSTRACT OF THE DISCLOSURE Apparatus for changing anode blocks in an aluminum furnace and for tapping and refilling the furnace provided with an anode changing device being adapted to travel along a mobile horizontal member; gripper means for handling an anode block; means for operating an anode clamp and a reservoir having its outlet directed towards the furnace; a lifting mechanism adapted to convey a tapping device and a reservoir on the horizontal member and having an outlet which is directed towards the filling opening of a silo associated with the furnace.

This invention relates to an apparatus for changing anode blocks in an aluminum furnace and for tapping and refilling said furnace.

In aluminum production plants it is conventional practice to dispose the aluminum furnaces in rows next to one another, the furnaces being disposed in both the longitudinal direction and in the transverse direction with respect to the building. Each furnace comprises a melting bath in which a number of anode blocks secured to rods are suspended. The thickness of these anode blocks decreases continuously during the electrolysis process, so that it is not only necessary to adjust the height of the anode block with respect to the melt in the furnace, but also change the anode block after some time. In addition, it is conventional practice to provide a relatively small silo for the supply of raw material (aluminum oxide) in the centre of each furnace. Of course, this silo has to be regularly refilled during the production process.

The anode blocks were hitherto replaced and the furnaces tapped and the silos refilled by means of separate devices or machines each requiring a separate operator, and this was a time-consuming and hence expensive procedure.

The object of the invention is to provide a system whereby all the above operations can be carried out economically and efiiciently.

To this end, the invention provides an apparatus of the type indicated above, comprising a mobile horizontal member, an anode changing device which is adapted to travel along said horizontal member and which is provided with remote-controlled percussion means for breaking the crust around the anode, remote-controlled gripper means for removing an anode block from the furnace and placing an anode block into the furnace, remote-controlled means for closing and opening an anode clamp, and a reservoir having its outlet directed towards the furnace; a remote-controlled lifting mechanism adapted to travel along the horizontal member to convey a tapping device from the furnace, and at least one reservoir disposed on the horizontal member and having a remotecontrolled outlet valve in the outlet pipe, the outlet opening being directed towards the filling opening of a silo associated with said furnace.

The advantage provided by the invention is that just one operator can carry out all the required operations with one machine to maintain the electrolysis process in a series of furnaces, and in addition, as a result of the reservoir secured in the horizontal member, the oper- 3,769,195 Patented Oct. 30, 1973 ator can provide the rows of furnaces with new raw material in a given pattern according to the way the process is carried out. The large reservoir which is secured to the horizontal member and which contains a multiple of the quantity required to refill a silo, is itself refilled at a central station at the optimum time for the process.

In a specific embodiment according to the invention, the horizontal member is constructed as a casing, with which the or each reservoir is formed integrally. Consequently, although the horizontal member is of relatively lightweight construction, the amount of raw material to be accommodated can be increased, so that the number of silos to be filled per reservoir charge, is increased, and this results in an economic process.

Finally, in order to counteract dust nuisance during the refilling of a silo, it is advantageous for the outlet pipe of each reservoir to consist of telescopic members.

The invention will be explained with reference to an exemplified embodiment of the apparatus illustrated in the drawing wherein:

FIG. 1 is a front elevation of the apparatus and the top part of an aluminum furnace with the associated silo.

FIG. 2 is a cross-section of the apparatus on the line IIII in FIG. 1.

Reference 1 denotes a horizontal member which is movable perpendicularly to the drawing plane on rails 4 supported by brackets 2 on the wall 3 of a factory shop. Although FIG. 1 shows only the support at the lefthand end of the horizontal member, it will be apparent that an identical support is provided at the other side of the horizontal member. In the same figure, an anode changing device having the general reference 5 is suspended from the horizontal member at the front thereof and in the drawing plane so as to be transportable. To this end, a rail '6 is provided on the one hand at the edge of the top surface of the horizontal member, and a wheel set 7 secured to the anode changer 5 runs on said rail, while on the other hand a rail 8 is provided at the bottom edge of the side surface of the horizontal member 1, with a wheel set 9 secured to the changer 5 running on the rail 8.

A control cab 11 rotatable about a vertical axis is disposed at the bottom of the frame 10 of the anode changer 5, and means for releasing the anode clamp and gripping the anode and denoted by references 12 and 13 respectively are secured to the rotating part of said cab in such manner that said means are always within the field of view of the operator in the cab 11. Percussion means rotatable about a vertical axis are also disposed at the bottom of the frame 10 of the anode system and comprises a pneumatic hammer 14 adapted to reciprocate vertically up and down by means of a parallel guidance system, the reciprocating movement being produced by a cylinder 15. The frame 10 of the anode changer 5 contains a reservoir 16, which merges at the bottom via valve 17 into an outlet 18 in the form of a pipe, the bottom end of which discharges near the top surface of the aluminum furnace.

A number of reservoirs 19 are formed integrally with the horizontal member 1 and contain the raw material for the aluminum preparation process. Each reservoir discharges at the bottom into a telescopic tube 20, a remotecontrol valve 21 being provided between the tube and the reservoir. The movable bottom parts of the telescopic tube 20 are all secured to a yoke 22 adapted to move up and down by means of a lifting mechanism. The reservoirs 19 can be filled at the top via a closable opening provided in the top surface of the horizontal member 1.

At the bottom right in FIG. 1 and at the bottom of FIG. 2 an aluminum furnace 23 with an associated silo 24 is illustrated diagrammatically. Six anode blocks 25 are suspended in the melting bath of the furnace 23. The anode blocks 25 are suspended by means of an anode rod secured to each anode block, said rod being clamped in a clamp 26. The clamps are secured to a yoke 27 which is disposed above the furnace and which is adapted to move up and down.

Finally, a lifting mechanism 28 is suspended from the horizontal member at the side thereof situated opposite the anode changer, the suspension being achieved in the same way as for the anode changer 5. This lifting mechanism is used to bring up and take away the crucibles into which the molten aluminum is tapped. This lifting mechanism is remote-controlled from the control cab 11.

The system operates as follows:

During the electrolysis process, the anode blocks burn uniformly at the bottom so that the yoke 27 has to be moved downwards to maintain good contact between the block and the melt. It will be apparent that one or more anode blocks have to be repleced at a given time in an aluminum furnace. For this purpose, the operator in the cab 11 drives the system to a position above the associated furnace and engages the gripper means 13 with the top of the anode rod. He then opens the anode clamp 26 with the means 12. There is a hard crust at the surface of the melt in the aluminum furnace 23 and the anode block is embedded therein. The hard crust around the anode block 25 must therefore be released, and this is done by the percussion means 14. FIG. 2 indicates the operative position of the percussion means 14 in broken lines. After the crust has been released, the anode block can be withdrawn from the furnace by lifting the gripper means 13 and can be deposited next to the furnace by movement of the system. Finally, in the reverse sequence, a new anode block disposed next to the furnace can be suspended in the exposed clamp 26. The hole formed by releasing the crust around the new anode block is filled up with raw material from the reservoir 16, the outlet pipe of which discharges at the associated anode.

Filling of the silo 24 is a separate procedure from the operations described above. Since the production of aluminum is a continuous process, a silo 24 is provided in the middle of each aluminum furnace and contains a limited supply of raw material. This limited supply must of course be regularly replenished. To this end, the operator in the cab 11 of the apparatus drives the outlet pipe 20 of the reservoir 19 to a position above the silo 24. He then lowers the bottom part of the outlet pipe into the silo in order to counteract dust nuisance during filling, whereupon filling can be carried out after the valve 21 has been opened. Of course the contents of the reservoir 19 are such that a number of silos 24 can be filled before the reservoir 19 itself has to be filled. This latter filling operation is carried out at a central station for the purpose in the factory shop.

The sequence of the anodes to be changed and the filling of the silos and the tapping of the molten aluminum depends upon the operational process and it Will be apparent that with the system according to the invention the process can be performed very efficiently.

What is claimed is:

1. In an aluminum production plant having a plurality of elongate aluminum furnaces arranged in parallel spaced relation, each furnace presenting an open-topped reservoir for receiving aluminum oxide and within which the aluminum production is carried out, a plurality of consumable anode blocksv disposed along the length of each furnace and means for positioning the anode blocks within the aluminum oxide received in each furnace and including an anode clamp for each anode, and a silo associated above each furnace and extending along the length thereof for replenishing aluminum oxide during the production process, the improvement which comprises:

a horizontal support member disposed above and parallel to said furnaces;

means for moving said support member selectively in registry with any one of said furnaces; anode changing means supported on said support member for movement to selected positions along its length, said anode changing means including percussion means for breaking the crust around a selected anode block, gripper means for removing a depleted anode from a furnace and positioning a new anodein its place, means for opening and closing an anode clamp, and means for supplying aluminum oxide around the new anode, said'anode changing means also including an operators station for remote control of the various aforesaid means; i

reservoir means positioned on said support member for filling a silo associated with any one of said furnaces; and

remote controlled lifting means movable along said support member for conveying a tapping device from any selected one of said furnaces. 1

2. The system as defined in claim 1 wherein said support member is in the form of a casing within which said reservoir means is integrally formed. I

3. The system as defined in claim 2 wherein said reservoir means comprises a plurality of separate reservoirs, each having separate discharge means associated therewith.

4. The system as defined in claim 3 wherein each discharge means comprises a telescopic pipe.'

5. The apparatus as defined in claim 1 wherein said anode changing means is supported on said support member in depending relation from and to one side of'said support member. t a v 6. The apparatus as defined in claim Swherein saidlifting means is supported on said support member'at that side thereof opposite to said one side at which the anode changing means is supported.

7. The apparatus as defined in claim 5 wherein said operators station, said gripper means and said means for opening are interconnected and rotatably supported about a first vertical axis.

8. The apparatus as defined in claim 7 wherein said percussion means is rotatably supported about a second vertical axis adjacent to but spaced from said first vertical axis.

9. For use in combination with a plurality of elongate aluminum furnaces arranged in parallel relation in a row; each furnace comprising a melting bath having a series of longitudinally spaced anode blocks suspended therein and a longitudinally extending silo disposed above the melting bath for controllably discharging raw material to the furnace; an apparatus for changing anode blocks in the furnaces and for tapping and refilling the furnaces, said apparatus comprising, in combination:

support means disposed along opposite sides of said row of furnaces;

an elongate horizontal member bridging between said support means for movement therealong to pass successively into alignment above each of said furnaces, said horizontal member including first reservoir means for controllably discharging raw material to said silos; carriage means supported on one side of said horizonta member for movement longitudinally thereof whereby to traverse the length of said furnaces; anode changing means including an operators cab rotatably suspended from said carriage means to said one side of the horizontal member; second reservoir means-carried by said carriage means for discharging raw material adjacent an anode block; and remote-controlled lifting means supported on the opposite side of said horizontal member independently of said carriage means on said one side for movement longitudinally of said horizontalmember to convey furnaces.

References Cited UNITED STATES PATENTS a tapping device to and from any selected one of said 6 FOREIGN PATENTS 1/1968 U.S.S.R. 204-245 JOHN H. MACK, Primary Examiner Schaper et a1 204245 X 5 D. R. VALENTINE, Assistant Examiner Duclaux 204225 X Capitaine et a1 204246 X 1 l- X.R-

Bogautes 204297 R 

